Help Letters after text message?

[Murf1]

Lately I've gotten some text messages and at the end it will say "[CB]" followed by their name. What does the "CB" mean and why does it do it sometimes and other times it does not on the same person?

 

[zuul]

i've been getting that and trying to figure it out as well

 

[sneaky_1]

It could have something to do with a call back setting in the messenger settings on one of the phones.

 

[Murf1]

I don't see a Call Back setting for the stock Msg app on my OE. So it must be on the other persons phone. (But it is not on all their msgs.)